There is no real evidence that ingesting any form of plastic will cause you any harm. During manufacture, or moulding of the containers, some plastics do release chemicals, mainly gases that can be extremely toxic (mainly Polyvinyl Chlorides - PVC's) but once the plastic has cooled, it is ok.
There has been suggestions down through the years that heating plastic in a microwave may release some of those toxins, but this has never been proved & there has been a lot of research done.
While I wouldn't recommend it, most forms of plastic (all of those that we come into contact with daily, anyway) can be consumed quite safely as the human body is incapable of breaking it down.
There is plenty of scaremongering & I would say that if this bothers you then stay away from plastic, but the reality is that there are people out there who think that Peanut Butter causes cancer, that you eat 8 spiders during your lifetime, that it takes 7 years for the body to break down chewing gum... etc
Allan